Or just AI denialists like to say "LLMs can't do X" even though they can and have been doing it for the past few months or more. They only get called out once the current SOTA LLMs get so good at it, that any rando can trivially and reliably falsify the claim on the spot with whatever SOTA LLM surface they have handy.

Which I suspect is what happened here, given the trail of smaller / local models that successfully answer the question, too.

That said, "curse of reversability" is real, as much for LLMs as it is for people.

I don't think it's solved this fundamental architectural problem by itself, it will have just squeezed the edge cases thinner. It keeps happening, people find a question it gets stupidly wrong, the vendors proclaim they've fixed it, then another one gets found.